Each year more than 35,000 people in the United States receive radiation therapy to treat head and neck cancer. Salivary glands in the irradiated field can suffer irreversible damage, markedly reducing salivary flow. For several years scientists at the National Institute for Dental and Craniofacial Research (NIDCR) have been developing a strategy for efficiently transferring a gene into irradiated salivary glands in an attempt to supplement or fully restore salivary production. Recently, NIDCR scientists and their colleagues in China evaluated the human aquaporin-1 gene (AdhAQP1) transfer strategy in a large, well-characterized animal model, the miniature pig. According to the online journal Molecular Therapy, the scientists found that the gene transfer significantly in-creased salivary secretions without causing significant side effects. In the pig model, 16 weeks after parotid gland irradiation (20 Gy), salivation from the targeted gland was decreased by more than 80%. On day 3 after human aquaporin-1 gene transfer, a dose-dependent increase in parotid salivary flow was found to be approximately 80% of preirradiation levels. The findings demonstrate that localized delivery of AdhAQP1 to radiation-damaged salivary glands increases salivary secretion without significant general adverse events in a large animal model.
Source: www.nidcr.nih.gov/NewsAndReports/ScienceNewsInBrief-1.htm Accessed February 7, 2005
